Gemstone



FIG. 1 is a top plan view of a gemstone showing my new design;

FIG. 2 is a bottom plan view thereof; and,

FIG. 3 is a front elevational view thereof, the left-side elevational view, the rear elevational view, and the right-side elevational view appearing the same as the front elevational view. 

CLAIM The ornamental design for a gemstone, as shown and described. 